Video endoscopes have been in general use since the 1980s for viewing the inside of the human body. Endoscopes are typically flexible or rigid devices that have an endoscope tip including an imaging unit, such as a digital camera or a scanned beam imager, configured for collecting light and converting the light to an electronic signal. The electronic signal is sent up a flexible tube to a console for display and viewing by a medical professional such as a doctor or nurse.
To improve performance, specialized endoscopes have been developed to best accomplish their intended function. For example, upper endoscopes are used for examination of the esophagus, stomach and duodenum, colonoscopes are used for examining the colon, angioscopes are used for examining blood vessels, bronchoscopes are used for examining the bronchi, laparoscopes are used for examining the peritoneal cavity, and arthroscopes are used for examining joint spaces. Instruments to examine the rectum and sigmoid colon, known as flexible sigmoidoscopes, have also been developed. The discussion of endoscopes herein generally applies to these and other types of endoscopes, and the term “endoscope” as used herein encompasses all these and other such devices.
Scanned beam endoscopes are a fairly recent innovation, and an example of a scanned beam endoscope is disclosed in U.S. patent application Ser. No. 10/873,540 (“'540 application”) entitled SCANNING ENDOSCOPE, hereby incorporated by reference and commonly assigned herewith. FIGS. 1 through 3 show a scanned beam endoscope disclosed in '540 application. As shown in the embodiment of FIG. 1, the scanned beam endoscope 100 includes a controller 102, monitor 104, and optional pump 106, all of which may be mounted on a cart 108, and collectively referred to as console 110. The console 110 communicates with a handpiece 112 through an external cable 114, which is connected to the console 110 via connector 116. The handpiece 112 is operably coupled to the pump 106 and an endoscope tip 120. The handpiece 112 controls the pump 106 in order to selectively pump irrigation fluid through a hose 126 and out of an opening of the endoscope tip 120 in order to lubricate a body cavity that the endoscope tip 120 is disposed within. The endoscope tip 120 includes a scanning tip 118 having a scanning module configured to scan a beam across a field-of-view (FOV).
The endoscope tip 120 and scanning tip 118 thereof are configured for insertion into a body cavity for imaging internal surfaces thereof. In operation, the scanning tip 118 scans a beam of light over a FOV, collects the reflected light from the interior of the body cavity, and sends a signal representative of an image of the internal surfaces to the console 110 for viewing and use by the medical professional.
FIGS. 2 and 3 depict the scanning tip 118 and a scanning module 127 of the scanning tip 118, respectively. Referring to FIG. 2, the scanning tip 118 includes a housing 130 that encloses and carries the scanning module 127, a plurality of detection optical fibers 132, and an end cap 131 affixed to the end of the housing 130. The detection optical fibers 132 may be disposed peripherally about the scanning module 127 within the housing 130. Referring to FIG. 3, the scanning module 127 has a housing 134 that encloses and supports a micro-electro-mechanical (MEMS) scanner 136 and associated components, an illumination optical fiber 138 affixed to the housing 134 by a ferrule 142, and a beam shaping optical element 140. A dome 133 is affixed to the end of the housing 130 and may be hermetically sealed thereto in order to protect the sensitive components of the scanning module 127.
In operation, the scanning tip 118 is inserted into a body cavity. The illumination optical fiber 138 outputs a beam 144 that is shaped by the beam shaping optical element 140 to form a shaped beam 146 having a selected beam shape. The shaped beam 146 is transmitted through an aperture in the center of the MEMS scanner 136, reflected off a first reflecting surface 148 of the interior of the dome to the front of the scanner 136, and then reflected off of the scanner 136 as a scanned beam 150 through the dome 133. The scanned beam 150 is scanned across a FOV and reflected off of the interior of a body cavity. At least a portion of the reflected light from the FOV (e.g., specular reflected light and diffuse reflected light also referred to as scattered light) is collected by the detection optical fibers 132. Accordingly, the reflected light collected by the detection optical fibers 132 may be converted to an electrical signal using optical-electrical converters, such as photodiodes, and the signal representative of an image may be sent to the controller 102 for image processing and the image displayed on the monitor 104. While the scanned beam endoscope 100 is an effective endoscope, the scanning tip 118 has a diameter that may be larger than desired for some applications due to the detection optical fibers 132 being positioned peripherally about the scanning module 127.